Five years ago, the Tufts Nutrition Collaborative - Center for Drug Abuse and AIDS Research (TNC-CDAAR) was funded in response to an RFA from NIDA as just one of two CDAAR's in the nation. The CDAARs were charged with the following mission: to foster a collaborative approach to drug abuse and addiction research; to enable studies that would not occur without the climate, facilities, and resources that a research center can uniquely provide; to serve as a resource to attract established and promising investigators into drug abuse research; and to provide opportunities for research training, career development, and mentoring. The TNC-CDAAR was formed as a partnership between three East Coast Institutions (Tufts, Brown and Johns Hopkins) with a specific focus on studying nutritional and metabolic disorders among HIV-positive and HIVnegative drug users. Over the past five years, we have expanded the TNC-CDAAR to include collaborators from 3 international sites: Argentina, India, and Vietnam. Our major accomplishments, thus far, have been to 1) design and implement several new studies to assess and compare the prevalence and incidence of specific nutritional and metabolic disorders in drug users of different ethnicities, both in the U.S. and abroad; 2) develop training materials, protocols, and manuals for investigators who want to undertake similar studies in their localities; 3) help in the development of new grant proposals in Center-related areas of research; and 4) become a resource center on nutrition and metabolic disorders in drug users. Specifically, the role of the Nutrition and Metabolism Core is to provide intellectual resources and training to support the work of collaborating investigators for nutrition and metabolic issues that are relevant to drug users who may or may not be HIV infected. The Core also provides services that foster the addition of nutrition and metabolic outcomes to projects, services that would otherwise not be available for researchers at the six collaborating sites. The Center also has been able to build infrastructure at member sites. Since the Center and its members are geographically separated, much of the Core's activities are focused on assisting investigators in the following: selecting nutrition and metabolic assessment parameters that are appropriate and feasible for the study and population; training investigators and personnel at the other sites to perform these selected nutrition and metabolic assessments properly; providing quality assurance for the nutrition and metabolic measures during the course of the study; assisting investigators in analyzing dietary intake data and interpreting the nutritional and metabolic data in the context of the study in which they were performed; archiving samples and ensuring standardized laboratory analyses through Core laboratories and providing laboratory analyses for metabolic outcomes as requested by Center investigators and members